Process for preventing gum formation in cracked gasoline



Aug. 13, 1935. '5. w. HOGE 2,011,556

PROCESS FOR PREVENTING GUM FORMATION IN CRACKED GASOLINE Filed Oct. 17, 1953 v I i 1'1 l 1/8 17 I A? I 1Q /5 W 1 1 1 5 k /3 7J I I M 1 $11 I I Iv I I ll 11 I I I I I I I 1 1 f- 1 DAN/EL, .IM/ia 6E INVENTOR.

ATTORNEY Patented Aug. 13, 1935 UNITED STATES PROCESS FOR PREVENTING GUM FORMA- TION IN CRACKED GASOLINE Daniel W. Hoge, Wilmington, Oalif., assignor to Charles P. Bitter, Long Beach, Calif.

Application October 17,1933, Serial No. 693,945

' .4 Claims.

This invention relates to fractionating towers and more particularly towers having a specific construction the purpose of which is to prevent I the formation of gummy constituents in petro- '5 leum liquid hydrocarbons, mixtures, or products from or of them. This tendency is very pro nounced in certain fractions, particularly gasolines, which have been produced by cracking processes, as the gum is highly objectionable since it causes stoppage in the jets of carburetors.

I have discovered that this tendency can be almost entirely eliminated by permitting the hydrocarbons or hydrocarbon mixtures being treated to come into contact with a certain combination or sequence of a certain combination of dissimilar metals. These metals are copper, aluminum and zinc, preferably, but not necessarily, arranged in the order named. The metals are each alloyed with about 30% to 50% of their weight of manganese to diminish chemical attack upon them.

The nature of the action of the dissimilar metals upon the hydrocarbons I am unable to explain by theory. I deduct from results obtained that there is some catalytic or electrolytic action, but I do not know its precise nature. I do know, however, that the desired effect is obtained by bringing the hydrocarbons alternately into contact with the metals when the former are in either the gaseous or liquid phase. The temperature I prefer to operate at is near the boiling points of the hydrocarbons being treated, but is not of great importance.

A very simple method of applying my invention is to make certain parts of the apparatus with which the hydrocarbons come into contact during their treatment, of the dissimilar metals. This apparatus should be used to handle the hydrocarbons after they have been distilled one or more times, but can be applied to the vapors of crude petroleum with like results.

In practice I have obtained particularly favorable results from my method by making shelves, trays, or plates of fractionating columns or towers of the three dissimilar metals named, these being arranged so that the aluminum plate is between the copper and zinc plates.

' With the above and other objects which may hereinafter appear in View the invention consists in the novel and useful provisions, formation, construction, association and interrelation of parts, members and features, all as shown in a certain embodiment in the accompanying drawing, described generally, and more particularly pointed out in the claims.

The accompanying drawing (one sheet) discloses one embodiment of my invention, namely a fractionating' tower, in which Fig. 1 discloses a vertical section, and Fig. 2 is plan view of the same. i

It is to be understood that the exact mechanical construction of a tower of this nature is not important, except in the materials used. The arrangement of bubble caps, vapor vents and other like details might be any like commercial construction used or usable for the same purpose.

In the drawing the outer wall I!) of the fractionating column is made of iron or other usual material. The wall, H), which is a series of cylindrical holl-ow unit sections or rather short unit lengths is adapted to be used as a unit to build up a tower in the customary manner. To this end each section is provided with flanges, produced by welding or riveting a ring of angle iron by one of its legs, l2, to the wall unit In. The flanges II are bolted or otherwise fastenedtogether by bolts or other suitable means. Clamped between the flanges H is a flat supporting ring I 4 extending inwardly in the column so as to form a narrow shelf.

It is upon the shelf I l that the plate or tray. l5 rests. The lower tray is made of zinc or copper, I the middle one of aluminum and the upper one of copper if the lower one is of zinc, or of zinc if the lower one is copper. Each of the plates is preferably, but not necessarily alloyed with 30% to 50% by weight of manganese. The latter content is the preferred one.

In each plate there is one or more vapor openings it, each rising several inches above the floor of the plate as a frustoconical boss. A cap I! with a serrated edge l8 surmounts each boss and is supported thereupon in such a manner as to leave channels for the escape of vapor from under the edge of the cap. Each plate also possesses a liquid drain pipe l9 which is held in a suitable bossed opening 20 and serves to return excess liquid to the next'lower plate. An outer flange 2| is provided to retain liquid. Each section may be also provided, if desired, with an individual liquid exit (not shown) to the outside of the column. The column, of course, is provided in the usual manner with a vapor inlet and a liquid outlet.

Instead of using the dissimilar metals as plates or trays in a column, the metals might also be present as the mingled shavings, chips, balls or irregularly shaped pieces of the three metals in question. No successive fractionation would of course be obtained unless plates were used, but the prevention of gum formation would be attained.

My method of using the above described column in the practice of my invention is to introduce hydrocarbon vapor into the bottom or side of the column in the usual manner and allow partial or entire condensation to the liquid state to occur therein. During the movement of the vapors and liquids through the column in the manner in which such movements usually occur, intimate contact of the hydrocarbon takes place alternately and successively with the copper, zinc and aluminum. This contact, in some unexplained manner prevents potential gum formation.

Certain modifications may present themselves to one versed in the art and such modifications may well be made without departing from the spirit of my invention as defined in the appended claims. 7 l

- I claim: I r s 1. A process for treating hydrocarbon compounds for preventing gum formation therein which comprises contacting such compounds with alloys of copper, aluminum and zinc with manand not more than 50% of each ofthe said metals. v I V 3. The process of preventing gum formation in cracked gasoline which comprises exposing such gasoline during the process of fractionation to contact a seriesv of dissimilar metals, one after the other, namely copper, aluminum and zinc,

alloyed .with not less than 30% or more than 50% manganese each.

'4. The process of preventing gum formation in cracked gasoline which comprises exposing such gasoline during the process of fractionation to contact a series of alloys of dissimiliar, metals, one after the other in the order named, namely copper, aluminum and zinc alloyed with not less than 30% or more than 50% manganese each.

DANIEL W. HOG-E. 

